FIGURE 5.

Yeast Ddp1p contains in vitro decapping activity. (A) Products of decapping assays with the indicated yeast Nudix proteins (50 nM) resolved by TLC are shown. The N-terminal 300 amino acids of yeast Dcp2p containing the catalytically active Nudix motif (Schwartz et al. 2003; Steiger et al. 2003) (Dcp2p 1–300) and recombinant mouse Nudt2 proteins were used as positive controls. Positions of decapping products are indicated at left. (B) Activity of the Ddp1p active-site EE-QQ mutant. Labeling is as described in the legend to Figure 1.